1. Field of the Invention
The present invention relates generally to portable and motorized power tools. More specifically, the present invention teaches an adaptive, ergonomic and multi-purpose air motor driven held-held tool which is capable of interchangeably holding a wide variety of tool bit attachments, and which can be flexibly incorporated into a variety of fixturing applications. Additionally, the present invention includes a coiled drive shaft providing the characteristics of flexibility, force and shock absorption; and which is capable of transferring high levels of torque to a tool bit or the like.
2. Description of the Prior Art
Conventional air motor driven and hand-held circular saw blade trimmers are known in the art and are used such as in the automotive industries for trimming synthetic materials in the fabrication of cushions. In general, these trimmer devices are designed with the air motor component arranged vertically in a cast aluminum housing, and with a handle extending downward at about a 45 degree angle and having an air supply hose attached to an end of the handle.
Such an arrangement places the weight of the unit very far forward of the wrist of the user, which must be held continually in a bent position, as well as exerting pressure on the base of the user's hand. Such conditions have been known to lead to the carpal tunnel syndrome which results from the median nerve, which passes through a narrow tunnel of the wrist (carpals), and a ligament at the base of the hand, being compressed by the surrounding tissue. Symptoms include numbness and pain in the hand and wrist. The condition often necessitates surgery to relieve pressure on the medial nerve.
Hand-held tools of this type shown in the prior art include that of U.S. Pat. No. 6,641,467, issued to Robson et al., which teaches a power tool including a motor pivotally mounted within a housing of the tool. The tool is able to accept any one of a plurality of attachment members such as a drill spindle head, reciprocating saw blade and the like.
U.S. Pat. No. 5,588,903, issued to Pennison, teaches an ergonomic power tool including a main body portion having a cavity and a handle portion coupled to the main portion. The main body portion has a first longitudinal axis and the handle portion a second longitudinal axis formed at an acute angle with respect to the first longitudinal axis. A coating of material is applied to an exterior of the handle portion to help minimize vibrations transferred to the operator's hand.
U.S. Pat. No. 4,751,922, issued to DiPietropolo, discloses an improved flexible medullary reamer for shaping the medullary space of bones. The shaft is comprised of a single and solid elongate element bored throughout its length. Attached to the shaft's opposite ends, respectively, are a cutting head and a means of connecting the shaft to a drive mechanism, both of which may also be internally bored.
U.S. Pat. No. 5,908,423, issued to Kashuba, teaches another variant of a flexible medullary reaming system and including a first reamer coupled to the distal end of a flexible shaft for rotation therewith and to prepare the distal portion of such as the medullary canal of a femur bone. A second reamer is coupled with the proximal portion of the shaft to form the proximal end of the lateral portion of the canal and/or the medial calcar region of the canal. A metaphyseal template having the shape of a prosthesis guides the reaming apparatus in forming the calcar region of the canal.
Finally, U.S. Pat. No. 5,820,464, issued to Parlato, teaches a flexible shaft assembly for transmitting rotary motion between spaced components that are mounted on articulated members. The flexible shaft exhibits a significant bending flexibility and includes a proximal section connected to a driver device, a distal section connector to a driven component, and an intermediate section. The proximal and distal sections are free to bend and rotate about a curved axis. One or more rigid sleeves are coaxially mounted on the intermediate section for reducing torsional deflections of the shaft as it rotates.